1891.] 



the Discharge of Leyden Jars. 



33 



number of them, the same number being taken in different parts of 

 the battery to secure fair uniformity. 



The following are the estimates of capacity made from these obser- 

 vations, the standard air-condenser being taken as 573 cm. : 



Capacity Measurements. 



The two jars supplied with the Voss machine happen to be, un- 

 fortunately, unequal. Their capacity in series was rather small to 

 actually measure satisfactorily : so I take it as 134 cm. 



First Approximation to Inductance of Circuit. 



35. In order to estimate the inductance of the discharge circuit, it 

 is necessary to know the following data : 



Thickness of the No. 17 wires 0'15 cm. 



Thickness of A discharging rods 0'60 



Thickness of rods inside Voss jars .... 0*98 



Thickness inside other jars 0'6 ,, 



Now, the discharge circuit consisted of a rectangle with one pair of 

 opposite sides made by certain length, w, of the No. 17 wires 50 cm. 

 apart, and with the other pair of opposite sides made by discharge 

 and jar rods, 50 cm. in length, and separated by a distance, u. 



I am not prepared to calculate the inductance of this rectangle 

 precisely, but when approximately square it makes but little differ- 

 ence whether I reckon it as a pair of parallel wires of length u, dis- 

 tance 50, and diameter 0'15, plus a pair of parallel rods of length 50, 



VOL. L. D 



